A student says every salt solution is neutral. Which example will disprove this statement?
Answer and explanation
Correct answer: Ammonium chloride
The governing concept is that the pH of a salt solution depends on the acid and base from which the salt is formed. Sodium chloride, from a strong acid and strong base, gives an approximately neutral solution. Ammonium chloride is formed from a strong acid, hydrochloric acid, and a weak base, ammonia; its aqueous solution is acidic because ammonium ions hydrolyse and produce hydronium ions. Therefore B disproves the claim, while the other choices do not provide an acidic salt solution.
Frequently asked questions
What is the correct answer to this question?
Ammonium chloride
Why is this the correct answer?
The governing concept is that the pH of a salt solution depends on the acid and base from which the salt is formed. Sodium chloride, from a strong acid and strong base, gives an approximately neutral solution. Ammonium chloride is formed from a strong acid, hydrochloric acid, and a weak base, ammonia; its aqueous solution is acidic because ammonium ions hydrolyse and produce hydronium ions. Therefore B disproves the claim, while the other choices do not provide an acidic salt solution.
Which subject and chapter does this question cover?
This is a Class 10 Science question. Chapter: Chemical Substances – Nature and Behaviour. Topic: Acids, Bases, and Salts.
